Is art an activity engaged in by the artist or is it a relationship between the artist and the viewer. If it is the first, then it would seem that the artist's only responsibility is to the art itself. If it is the latter, then it seems like the artist has a responsibility to the viewer, to try to make the artistic relationship meaningful. Consider, say, Andy Kaufman whose comedy was so far out that audiences were left speechless at best, angry at worst. Is catering to your audience cheapening the art, turning it into mere entertainment or is it an essential part of engaging others artistically? Does the artist have to consider his audience at all?